The present invention is directed toward a defibrillation catheter and more particularly, toward a method and apparatus for facilitating intracardiac atrial defibrillation.
Atrial defibrillation is a common arrhythmia that afflicts more than 1.5 million patients in the U.S. alone. It is by far the most prevalent cardiac rhythm disorder associated with hospitalization. Symptoms associated with chronic atrial fibrillation include: awareness of irregularity, palpitations, fatigue, and diminished exercise tolerance. Atrial fibrillation has also been recognized as one of the main contributing factors of embolic strokes.
The risks and symptoms associated with atrial fibrillation confirm the necessity for restoration of sinus rhythm. Two commonly employed methods for performing an intracardiac atrial defibrillation procedure are drug therapy and external cardioversion. With regard to drug therapy, studies have shown that there is a risk for proarrhythmic effects, especially in patients with atrial fibrillation and a history of congestive heart failure, which may outweigh the potential benefit of restoring sinus rhythm.
There are also risks associated with external cardioversion. Such risks result form the fact that high energy shocks (50 to 360 Joules) are used during the procedure. The high energy shocks can cause heavy muscular contractions with a potential risk of spine or bone fractures, potential pronounced increase in muscle enzymes, induction of ventricular arrhythmias, and overall negative influence on myocardial function. Further, the high energy shocks require the administration of a general anesthetic.
In recognition of the foregoing, a method involving internal cardioversion using percutaneous transvenous catheter electrodes has been developed. Internal cardioversion can be performed with energies of less than 12 Joules. However, existing multi-electrode catheters typically do not have the proper arrangement of electrodes to provide the necessary electroshocks to the appropriate locations.
The present invention is designed to overcome the deficiencies of the prior art discussed above. It is an object of the present invention to provide a catheter for facilitating atrial defibrillation that uses three electrode arrays on a single catheter.
It is a further object of the present invention to provide a method of performing intracardiac atrial defibrillation.
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a catheter for facilitating intracardiac atrial defibrillation that includes an elongated flexible member that has a proximal end and a distal end. Three spaced apart electrode arrays are secured around the periphery of the flexible member in a predetermined pattern so that a first electrode array is adapted to positioned within the superior vena cava, a second electrode array is adapted to be positioned within the right atrium, and a third electrode array is adapted to be positioned within the coronary sinus. Alternatively, the third electrode array may be positioned in the right ventricle rather than the coronary sinus. Electrical leads extend through the flexible member to supply electrical current to the electrode arrays. In other embodiments, a balloon envelope is also secured to the periphery of the flexible member adjacent the distal end of the flexible member.
Other objects, features, and advantages of the invention will be readily apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the drawings.